Notifying an owner that messages that have been recorded on the incoming call recording tape in a telephone answering device is a convenient means to keep track of the receipt of important messages. This is particularly important for businessmen or people who are frequently away from home for extended periods of time. Such a system differs from TAD's that permit the owner to call his own TAD and retrieve, by use of a predetermined code or frequency, messages that have been recorded on the TAD played back to the owner, since such a system requires the owner to call the TAD repeatedly.
One message transfer system associated with a TAD is disclosed in the patent to McClure, U.S. Pat. No. 4,065,642. In the McClure device, if a person wishes to be notified that a message has been recorded by the TAD, the TAD is programmed to dial the preprogrammed telephone number where the owner intends to be reached. When the TAD detects that a new message has been received and stored in the Incoming Call Record (ICR) tape, the TAD automatically dials the preprogrammed number. If the call from the TAD is answered, the TAD sends a signal over the telephone line in the form of a tone, which is meant to alert the recipient of the call that a message has been recorded on the TAD. The recipient can then cause the TAD to play back the message recorded by entering the correct security code. There is no audio message indicating the meaning of the tone. After the recorded message has been played, the TAD disconnects the line and waits for the next incoming call.
In the McClure device, if the message transfer system finds the recipient's telephone number to be busy, it repeatedly dials the number allowing a certain time interval between successive attempts until the call is answered within a predetermined time limit. If the call is not answered within this time limit, it ceases its attempts to transfer the message.
In another prior art device sold by Panasonic, Model KX-T2632, the TAD calls the preprogrammed telephone number and plays the same message that it normally plays to prompt the caller to leave message.
Both the Panasonic and McClure devices have serious shortcomings. Unless the party receiving the message transfer call has prior knowledge of the meaning of the tone signal, he or she is likely to be confused. The tone signal that is generated by the McClure device provides no clue as to what it is. The recipient may not even realize that it is a message transfer signal. Similarly, in the Panasonic device, playing a message that prompts recipient of the call to leave d message wouldn't make any sense to someone who is not aware that it is a message transfer signal. Thus, in both instances, the recipient of such a call, especially if the recipient is one other than the TAD owner, is likely to just hang up.
Multiple messages on a single tape that can be played back to a caller have been employed, such as in the patent to Bond, U.S. Pat. No. 4,571,458. In the Bond patent, the caller is prompted to input a code if a particular message is desired. Also, in the patent to Eswaran, U.S. Pat. No. 4,847,889, different portions of an ICR tape can be accessed to play back different portions of a recorded tape. None of the above devices, however discloses use in a message transfer system as according to the present invention, as set forth hereinbelow.